i386: move math-emu

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 135 insertions, 0 deletions

diff --git a/arch/x86/math-emu/polynom_Xsig.S b/arch/x86/math-emu/polynom_Xsig.S
new file mode 100644
index 00000000000..17315c89ff3
--- /dev/null
+++ b/arch/x86/math-emu/polynom_Xsig.S
@@ -0,0 +1,135 @@
+/*---------------------------------------------------------------------------+
+ |  polynomial_Xsig.S                                                        |
+ |                                                                           |
+ | Fixed point arithmetic polynomial evaluation.                             |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1995                                         |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail billm@jacobi.maths.monash.edu.au |
+ |                                                                           |
+ | Call from C as:                                                           |
+ |   void polynomial_Xsig(Xsig *accum, unsigned long long x,                 |
+ |                        unsigned long long terms[], int n)                 |
+ |                                                                           |
+ | Computes:                                                                 |
+ | terms[0] + (terms[1] + (terms[2] + ... + (terms[n-1]*x)*x)*x)*x) ... )*x  |
+ | and adds the result to the 12 byte Xsig.                                  |
+ | The terms[] are each 8 bytes, but all computation is performed to 12 byte |
+ | precision.                                                                |
+ |                                                                           |
+ | This function must be used carefully: most overflow of intermediate       |
+ | results is controlled, but overflow of the result is not.                 |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+	.file	"polynomial_Xsig.S"
+
+#include "fpu_emu.h"
+
+
+#define	TERM_SIZE	$8
+#define	SUM_MS		-20(%ebp)	/* sum ms long */
+#define SUM_MIDDLE	-24(%ebp)	/* sum middle long */
+#define	SUM_LS		-28(%ebp)	/* sum ls long */
+#define	ACCUM_MS	-4(%ebp)	/* accum ms long */
+#define	ACCUM_MIDDLE	-8(%ebp)	/* accum middle long */
+#define	ACCUM_LS	-12(%ebp)	/* accum ls long */
+#define OVERFLOWED      -16(%ebp)	/* addition overflow flag */
+
+.text
+ENTRY(polynomial_Xsig)
+	pushl	%ebp
+	movl	%esp,%ebp
+	subl	$32,%esp
+	pushl	%esi
+	pushl	%edi
+	pushl	%ebx
+
+	movl	PARAM2,%esi		/* x */
+	movl	PARAM3,%edi		/* terms */
+
+	movl	TERM_SIZE,%eax
+	mull	PARAM4			/* n */
+	addl	%eax,%edi
+
+	movl	4(%edi),%edx		/* terms[n] */
+	movl	%edx,SUM_MS
+	movl	(%edi),%edx		/* terms[n] */
+	movl	%edx,SUM_MIDDLE
+	xor	%eax,%eax
+	movl	%eax,SUM_LS
+	movb	%al,OVERFLOWED
+
+	subl	TERM_SIZE,%edi
+	decl	PARAM4
+	js	L_accum_done
+
+L_accum_loop:
+	xor	%eax,%eax
+	movl	%eax,ACCUM_MS
+	movl	%eax,ACCUM_MIDDLE
+
+	movl	SUM_MIDDLE,%eax
+	mull	(%esi)			/* x ls long */
+	movl	%edx,ACCUM_LS
+
+	movl	SUM_MIDDLE,%eax
+	mull	4(%esi)			/* x ms long */
+	addl	%eax,ACCUM_LS
+	adcl	%edx,ACCUM_MIDDLE
+	adcl	$0,ACCUM_MS
+
+	movl	SUM_MS,%eax
+	mull	(%esi)			/* x ls long */
+	addl	%eax,ACCUM_LS
+	adcl	%edx,ACCUM_MIDDLE
+	adcl	$0,ACCUM_MS
+
+	movl	SUM_MS,%eax
+	mull	4(%esi)			/* x ms long */
+	addl	%eax,ACCUM_MIDDLE
+	adcl	%edx,ACCUM_MS
+
+	testb	$0xff,OVERFLOWED
+	jz	L_no_overflow
+
+	movl	(%esi),%eax
+	addl	%eax,ACCUM_MIDDLE
+	movl	4(%esi),%eax
+	adcl	%eax,ACCUM_MS		/* This could overflow too */
+
+L_no_overflow:
+
+/*
+ * Now put the sum of next term and the accumulator
+ * into the sum register
+ */
+	movl	ACCUM_LS,%eax
+	addl	(%edi),%eax		/* term ls long */
+	movl	%eax,SUM_LS
+	movl	ACCUM_MIDDLE,%eax
+	adcl	(%edi),%eax		/* term ls long */
+	movl	%eax,SUM_MIDDLE
+	movl	ACCUM_MS,%eax
+	adcl	4(%edi),%eax		/* term ms long */
+	movl	%eax,SUM_MS
+	sbbb	%al,%al
+	movb	%al,OVERFLOWED		/* Used in the next iteration */
+
+	subl	TERM_SIZE,%edi
+	decl	PARAM4
+	jns	L_accum_loop
+
+L_accum_done:
+	movl	PARAM1,%edi		/* accum */
+	movl	SUM_LS,%eax
+	addl	%eax,(%edi)
+	movl	SUM_MIDDLE,%eax
+	adcl	%eax,4(%edi)
+	movl	SUM_MS,%eax
+	adcl	%eax,8(%edi)
+
+	popl	%ebx
+	popl	%edi
+	popl	%esi
+	leave
+	ret